A method for the simultaneous determination of 24 water soluble synthetic colors in premade cocktails was developed using ultra performance liquid chromatography with diode array detector(UPLC-DAD).In this paper,the chromatographic conditions for mobile phase,column and eluting gradient were optimized,and the best separation conditions were as follows:column:a Waters BEH C18 column(2.1 mm×50 mm,1.7 μm),mobile phase:10 mmol/L ammonium acetate solution (pH 625) and methanol-acetonitrile(2∶8,by volume),eluting by a gradient program.Under the optimized conditions,all the water soluble synthetic colors could be rapidly separated within 16 min.There were good linear relationships for the analytes in the concentration range of 0.01-50.0 mg/L with their correlation coefficients(r2) greater than 0.998 0.The limits of detection(LOD,S/N=3) and the limits of quantitation were in the ranges of 0.66-27.78 μg/L and 2.19-92.59 μg/L,respectively.The intra day and inter day RSD for the analytes were in the ranges of 0.04%-5.3% and 0.08%-6.4%,respectively.The recoveries for the synthetic colors ranged from 53.4% to 114%.With the advantages of many kinds of dyes detected,short analysis time and low detection limit,the method was successfully applied in the determination of cocktail samples on the market.